© Norwegian Journal of Entomology. 22 December 2020

Polia lamuta (Herz, 1903) (, ) discovered in Norway, and notes on other boreo-montane

HANNU SAARENMAA

Saarenmaa, H. 2020. lamuta (Herz, 1903) (Lepidoptera, Noctuidae) discovered in Norway, and notes on other boreo-montane species. Norwegian Journal of Entomology 67, 189–195.

A single male of Polia lamuta (Herz, 1903) was found on the Iškoras mountain in Karasjok, Troms og Finnmark on 15–19 July 2020 with a bait trap. The discovery was expected since the species occurs widely in Northern Finland close to the Norwegian border and in the northernmost Sweden as well. The species lives in sandy, dry and sunny habitats and belongs to the boreal Palearctic continental fauna. Its , morphology, ecology, and behavior are briefly reviewed. Occurrence of other boreal Noctuids such as Polia vesperugo Eversmann, 1856 and Xestia gelida (Sparre-Schneider, 1883) in the region is discussed.

Key words: Lepidoptera, Noctuidae, Polia lamuta, Iškoras, new record.

Hannu Saarenmaa, Adjunct Professor, Department of Forest Sciences, University of Helsinki, P.O. Box. 27, FI-00014 Helsinki. E-mail: [email protected]

Introduction raised which meaningful discoveries could be made which would benefit from our experiences In most summers in the past decade the author in , and are there any white spots on the has spent extensive time studying Lepidoptera map that could be filled? in Russia, first in Karelia and Archangelsk and From the mountains in Karigasniemi (Utsjoki, then in Buryatia and Transbaikalia in Eastern Finland) we have often viewed the massive Siberia (Saarenmaa et al. 2016). The motivation Iškoras mountain (height 644 m a.s.l.) on the is that in the core area of the distribution of the Norwegian side of the Tana river (Troms og Siberian species, where they can be observed Finnmark province, Karasjok municipality) and daily in numbers, one can quickly learn much wondered what Lepidoptera could be collected of their ecology and behavior. This is difficult in there. Search on the Artsdatabanken (2020) Fennoscandia where these species are at the far system did not reveal much – maybe the place has end of their range, are rare, and only seldom can not been visited systematically. be observed. For instance, the immature stages We reasoned that the Iškoras mountain might of (Matsumura, 1925) were house some rare boreal continental species such described as a result of our 2013 expedition (Ahola as Polia lamuta (Herz, 1903) and Polia vesperugo et al. 2015). We now are readying an article of Eversmann, 1856, which have been reported from Arctia menetriesii (Eversmann, 1846) (Tähtinen Karigasniemi area in Finland but had not yet been et al., in prep.). found across the river in Norway (cf. Aarvik et al. In the summer 2020, the planned trip to Russia 2017) (cf. Figure 1). had to be cancelled which opened an opportunity As a side note, it should be stated that the latter- to work again in Lapland. The question was mentioned species Polia vesperugo was until the

189 Saarenmaa: Polia lamuta discovered in Norway

FIGURE 1. Map of Polia lamuta (Herz, 1903) records from FinBIF Portal (2020). The Iškoras mountain is shown with a red arrow. recent revision of Varga et al. (2017), known by places. So, an expedition to the Iškoras mountain the synonym (A. Bang-Haas, had to be made. 1912). The species was for the first time detected in Finland at the Saariselkä mountain range in 1980 and at that time, lacking to access to Russian Material and methods collections, was believed to be a species new to the science. It was given the name Polia sabmeana On 15 July 2020, the author placed 8 bait traps in Mikkola, 1982. Since then older specimens have pairs at 4 different altitudes (290 m, 320 m, 400 been picked up from collections and it has become m, and 470 m a.s.l.) near the road that leads to the obvious that this large and distinct species had top of the Iškoras mountain. When the traps were been present in Lapland all of the time but had removed on 19 July 2020, one worn-out male Polia been mixed with another, remotely related species lamuta specimen was found in a beer-based trap Apamea kuusamoensis (Aro, 1900). So, we had at the lowermost altitude. Geographic coordinates large white spots on the map and right in the front (WGS84) are N69.34723, E025.19981, and of our view. accuracy 10 m. Weather during this period was According to our experiences in Finland and in sunny in the beginning but became rainy towards Siberia, these and other boreal Noctuid species can the end. Accumulation of the thermal sum in 2020 with proper techniques be found using trapping was slow which must be taken into account when and by systematic search in their potential resting considering the phenology of the species.

190 Norwegian Journal of Entomology 67, 189–195 (2020)

FIGURE 2. The specimen of Polia lamuta (Herz, 1903) from the Iškoras mountain at Karasjok, Finnmark, Norway 15–19 July 2020. The specimen has been deposited in the collection of the Arctic University Museum of Norway, University of Troms, under the accession number TSZL-023768.

On 28 July 2020, ten bait traps were placed at the 400 m location by Kari Tahvanainen and Jukka Tiittanen. These traps were removed a month later, on 28 August 2020 by Jukka Tiittanen and the author. Trapping only at this altitude was chosen to aim at Polia vesperugo, but none was found. Our Polia lamuta specimen is illustrated in Figure 2. It has been deposited in the Arctic University Museum of Norway, University of Tromsø, and its accession number is TSZL- 023768. FIGURE 3. Jukka Tiittanen pictured on 28 August A list of all Lepidoptera species which were 2020, holding two bait traps at an altitude of 400 m on observed and could be identified is given in Table the Iškoras mountain. 1. Noteworthy is Xestia gelida (Sparre-Schneider, 1883) of which a male specimen arrived in the those manufactured and sold by the purveyor to beer-based trap at the lowermost altitude. After the Lepidopterological Society of Finland, the the holotype specimen was found in Sør-Varanger company Tibiale Ltd (www.tibiale.fi). The model in 1882 (see Aarvik & Christiansen 2011), this is of the trap is 0623-S. As bait in the first attempt the only other record of the species in Troms og both beer-based and wine-based mixtures were Finnmark. used at each altitude. In the second attempt only The bait traps (Figure 3) which were used are beer-based mixture was employed. As killing

191 Saarenmaa: Polia lamuta discovered in Norway

TABLE 1. List of Lepidoptera species from the Iškoras mountain in 2020. The columns are: A. Systematic number from Karsholt & Razowski (1996); B. Scientific name, from the above catalog; C. Number of observed individuals at the altitude 290 m on 15–19 July 2020 using 2 bait traps; D. Number of observed individuals at altitudes over 320 m in the same period using 6 bait traps and netting; E. Number of individuals at 400 m on 28 July–28 August 2020 using 10 bait traps A B C D E 4743 Phiaris metallicana (Hübner, 1799) 1 4744 Phiaris schulziana (Fabricius, 1776) 5 4844 Epinotia solandriana (Linnaeus, 1758) 1 5704 Polopeustis altensis (Wocke, 1862) 2 7013 Colias palaeno (Linnaeus, 1761) 2 7410 Erebia pandrose (Borkhausen, 1788) 1 7588 Macaria fusca (Thunberg, 1782) 100 4 8067 ternata (Schrank, 1802) 10 8250 Xanthorhoe abrasaria (Herrich-Schäffer, 1855) 3 8302 caesiata (Denis & Schiffermüller, 1775) 49 8332 Eulithis populata (Linnaeus, 1758) 12 8346 Dysstroma infuscatum (Tengström, 1869) 1 2 8444 Epirrita autumnata (Borkhausen, 1794) 28 8526 Eupithecia satyrata (Hübner, 1813) 10 8783 auricoma (Denis & Schiffermüller, 1775) 5 3 9074 Syngrapha interrogationis (Linnaeus, 1758) 1 9536 Parastichtis suspecta (Hübner, 1817) 1 9655 Lithomoia solidaginis (Hübner, 1803) 43 9989 biren (Goeze, 1781) 1 9997 Polia lamuta (Herz, 1903) 1 10062 (Linnaeus, 1758) 2 10089 Diarsia mendica (Fabricius, 1775) 10 6 10093 Diarsia rubi (Vieweg, 1790) 20 32 10161 Eurois occultus (Linnaeus, 1758) 1 10192 Xestia gelida (Sparre-Schneider, 1883) 1 10194 (Zetterstedt, 1839) 20 58 43 10198 Xestia tecta (Hübner, 1808) 1

agent in the collecting jars tetrachlorethane Taxonomy and morphology was used, which evaporates slowly and hence facilitates very long operating times between trap According to Varga et al. (2017), Polia lamuta visits (that is, when catches are small and do not was first described by the name lamuta fill the jars). Herz, 1903. Type-locality is in Russia, at the Uruata Camp place, west of Verkhoyansk, in the current Republic of Sakha (Yakutia). Syntypes

192 Norwegian Journal of Entomology 67, 189–195 (2020) are 1 male and 1 female, held in the collection Lapland often follow a dune-mire mosaic-looking of the Zoological Institute, Russian Academy of landscape pattern. The habitat of the discovery site Sciences, St. Petersburg. is shown in Figures 4 and 5. It is characterized by Interestingly, the epithet asiatica was first mountain ( czerepanovii) used for another taxon, based on a specimen and scattered large Scots pine trees (Pinus from Dovre, Norway, held in the collection of sylvestris). the Museum für Naturkunde, Berlin, to describe The immature stages of Polia lamuta have Anarta richardsoni var. asiatica Staudinger, been described by Ahola (1986). In captivity its 1901. However, the combination with the have fed on uliginosum, name Polia Ochsenheimer, 1816, the epithet , and Polygonum sp. (Ahola was pre­occupied, and became a junior secondary and Silvonen 2008). It overwinters first as small homonym of Polia asiatica Alphéraky, 1887. larva and for a second time as full-grown larva The name of that taxon soon turned out to be a that does not eat anything after over-wintering. synonym of Bryoxena centralasiae (Staudinger, In most of northern Fennoscandia the species is 1882). on the wing only on even-numbered years, but The closest relative to Polia lamuta is Polia in Easternmost Finland, Kola Peninsula, and richardsoni (Curtis, 1835). While the latter has eastwards on odd-numbered years. Hence, it a Holarctic distribution and belongs to the high follows the parasitism-driven alternate-year flight mountains, the former is restricted to the Palearctic pattern of many other boreal Noctuids (Mikkola region and lives in forested environments. 1976). This means that adults of Polia lamuta and There are records in databases from the many other boreal Noctuids cannot be found on Nearctic region (Greenland) which the author has Iškoras in the year 2021 but first on 2022. investigated but these belong to . Based on the 297 records from Finland The two species can easily be differentiated by (FinBIF Portal 2020), Polia lamuta is on the their wing form and the color and markings in the wing in early and middle July. According to hindwing. The dark central spot in the hindwing the collectors consulted (see the section of is always in different position in these two species. Acknowledgements) it flies typically in sunshine Really, Polia lamuta resembles a double-size in the afternoon and in the evening. It does not Conanarta cordigera (Thunberg, 1788) but not fly at night and, to the author’s knowledge, has with yellow but white rear wings. not been taken by light at night in Siberia where Nevertheless, obvious hybrids of the two it flies at lower latitudes where nights are dark. It species Polia lamuta and Polia richardsoni have can be found sitting on tree trunks, fence poles, been found in Utsjoki at Karigasniemi Ailigas etc., during the night, mornings, and at cloudy mountain where the ranges of the two species weather. The species flies very fast and rather low meet (see images and discussion by Pakkanen over the shrubby vegetation. Because its large 2019). size and striking white rear wings it can easily be recognized during the flight but is hard to catch by netting. The flight behavior is quite similar to Ecology and behavior those of the closely related species Conanarta cordigera and Anarta myrtilli (Linnaeus, 1761), Polia lamuta has a Palearctic distribution. There which have yellow rear wings, but can easily be are records from Magadan across Siberia all the recognized because it is nearly twice the size of way to Swedish Lapland (FinBIF Portal 2020). these species and its white rear-wings. Compared Polia lamuta lives in boreal forests and with the more distantly related species Sympistis (according to Erkki M. Laasonen and Leena heliophila (Paykull, 1793) which lives in the same Laasonen; personal communication) prefers dry habitat, is abundant, and does have white rear sandy soil and sunny exposure where few other wings, Polia lamuta is double in the size and flies Lepidoptera species can be seen. Such habitats in much faster and without whirling about.

193 Saarenmaa: Polia lamuta discovered in Norway

FIGURE 4. View of the habitat where the specimen was caught at the altitude 290 m.

FIGURE 5. View of a habitat at about 250 m, by the Iškoras road, that resembles more of the sunny, exposed habitats of the species in Finland, and according to our views is most suitable for Polia lamuta (Herz, 1903).

194 Norwegian Journal of Entomology 67, 189–195 (2020)

Discussion Jürivete, U., Karsholt, O., Mutanen, M. & Savenkov, N. 2017. Nordic-Baltic checklist of Lepidoptera. The discovery of Polia lamuta in Finnmark was Norwegian Journal of Entomology, Supplement 3, result of a targeted search. Without question the 1–236. species has always lived in that location and can Aarvik, L. & Christiansen, C. 2011. Xestia gelida (Sparre Schneider, 1883) (Lepidoptera, Noctuidae) be found there again. It has remained hidden rediscovered in Norway. Norwegian Journal of because inner Finnmark is a faraway area only Entomology 58, 1–6. seldom visited by collectors, the species is on the Ahola, M. 1986. Larvae of European Polia wing only on even-numbered years, and capturing Ochsenheimer (Lepidoptera, Noctuidae), with it requires specific methods which have only lately proposals on a subgeneric division and phylogeny. become developed and widely known. Entomologica Scandinavica 17, 55–74. Like Xestia gelida and Polia vesperugo, the Ahola, M., Kuisma, M., Leinonen, R., Saarenmaa, H. species remained for a long time quite a rarity, & Silvonen, K. 2015. Description of immature stages but in recent years has become a regular catch. of Xestia brunneopicta (Matsumura, 1925), with a These species belong to an extremely continental, key to the mature larvae of the European species of Siberian faunistic element that also live in dry and Xestia (Pachnobia) (Lepidoptera, Noctuidae). Nota Lepidopterologica 38(1), 75–88. warm soil and hence may have been favored by Ahola, M. & Silvonen, K. 2008. Larvae of Northern the warming climate. European Noctuidae, volume 2. KuvaSeppälä- We did not capture Polia vesperugo yet from yhtiöt Oy, Vaasa. 672 p. Iškoras, which was somewhat unexpected. The Artsdatabanken. 2020. Artskart (https://artskart. species seemed to have a bad year, as the slim artsdatabanken.no/). Accessed 1 May 2020. number of records in 2020 from Finland also seem FinBIF Portal 2020. Finnish Information to indicate. Polia vesperugo in Fennoscandia lives Facility. Accessed for 328 Polia lamuta records in mountains at the treeline, which is somewhat on 3 August 2020. https://laji.fi/en/observation/ higher an altitude to where Polia lamuta occurs. list?target=MX.62856 That is why we covered a range of altitudes with Herz, O. 1903. Verzeichniss der auf der Mammuth- our traps and in the end placed ten bait traps for Expedition gesammelten Lepidopteren. Annuaire du Musée zoologique de l’Académie impériale des a month right onto the treeline. Polia vesperugo sciences de St.-Pétersbourg 8, 61–87. in Siberia is not rare, but a generalist that flies Karsholt, O. & Razowski, J. 1996. The Lepidoptera mainly in the forest region, usually late in the of Europe. A Distributional Checklist. 382 p. Apollo night, and comes eagerly to light traps. For bait Books. Stenstrup. traps come mainly females towards the end of Mikkola, K. 1976. Alternate-year flight of Northern the flight period. With this knowledge, maybe Xestia species (Lep., Noctuidae) and its adaptive in coming years also this other white spot on the significance. Annales Entomologici Fennici 42, Norway map will be filled. 191–199. Pakkanen, P. 2019. Idänkehnäyökkönen (http:// perhoset.perhostutkijainseura.fi/historia// Acknowledgements. The author thanks his expedition pol-lamuta.htm). Accessed 17 September 2020. companions Jukka Tiittanen and Kari Tahvanainen for their Saarenmaa H, Tiittanen J, Alestalo P. 2016. efforts and advice in the field work. Thanks also to Erkki M. Perhostieteellinen tutkimusmatka pohjoiseen Taka- Laasonen and Leena Laasonen for their insight of Polia lamuta Baikaliaan. Abstract: Lepidopterological expedition ecology and behavior which has been cited above. Thanks also to northern Trans-Baikalia. Baptria 41(2), 50–61. for Leif Aarvik, Lars Ove Hansen, and Kimmo Silvonen for Varga, Z., Ronkay, G. & Ronkay, L. 2017. Revised their comments on the manuscript. taxonomic check list of the Eurasiatic species of the subtribe Poliina (Noctuidae, , Hadenini). Deutsche Entomologische Zeitschrift 64(2), 133– References 160, doi:10.3897/dez.64.21455

Aarvik, L., Bengtsson, B.-Å., Elven, H., Ivinskis, P., Received: 4 October 2020 Accepted: 16 November 2020

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